Telephone receiver



June 5, 1928. 1,672,294

N. BALDWIN TELEPHONE RECEIVER Filed Jan 29, 1925 j if,

ruvsu'rog Patented June 5, 1928 NATHANIEL BALI DWIN, F Ens'r Mm; cE Ex, UTAH.

TELEPHONE nEcEIvEn.

Application filed aniiary tioned patent.

The objects of the present invention are to provide a convenient arrangement and magnetic connection of such polepieces, to provide a suitable support for the armature 16 and to provide means to use the armature itself instead of a regular diaphragmfora sound producing element, thus eliminating the armature fulcrum, spring, diaphragm,

and connecting" link shown n the several figures of the said patent.

I attain these and other objects by the mechanism illustrated in the accompanying drawing in which Fig. 1 is a back view of the instrument with" part otthe shell and part vof the magnet cut away; Fig. 2 is a partial sectionof the instrument along the line A B of Fig. 1 showing"parts in elevation. v.Fig. 3 is across-section of the instrumentalong the line C D of Fig. 1;-Fig. 4 is a bac-kview of-a modified form of the structure shown in Fig. 1. Fig. 5 is a longitudinal section of a modified form of ar-v mature and Fig. 6 is an elevation of the same.

,5 In the several figures numeral 1 designates the earpiece of the receiver which in the presentstructure forms a base to which the several parts,are secured and held in proper space relations. 7 The spool 2 isa structure similar to that shown in in former patent but has'nov fulm provi ed init.- It is inclosed' and heldin 1position by the polepieces 3 and 4. These; p0 epieces are. formed by bending fiatlbars 5 of iron into U-shapedpieces with the 1 per part of one limb and the lower part 0 the other cut away and fittogether over the spool as shown. Projecting edges 5, 5and 6, 6 formed on the limbs of the polepieces o engage the straight edges of the spool 2 and hold it in proper position and the properspacing between the polepieces'is alsomaintained.

p The poles of-the magnet 7 are joined to 5 the middle wide portions of the polepieces 3,,

29, 1925. seiiarm. 5,511

and 4 and these'tlparts combinedpmagnet poles; polepie'ces,-arid spool are set into a rectangular recess formed in the earpiece 1.

- Upstanding lugs' 8, 8 atthe ends of this recess are provided and screws 9, '9 passin through these. lugs,-through the magnet and tapped into the polepieces 3 and 4 hold these parts fi mlyin lace.'-

Transverse y to t e recess above mentioned a shallow recess 10 is formed in the earpiece 1 over whichis placed the armature 11 which armature passes through the spool 2 and between the limbs of'thpolepieces 3 and 4 without touching either'and extends across the said shallow recess 10, over bridges 1-2, 12 on either side and h'as its ends fastened under clamps 13,113 which are adjusted by screws 1 14. It will be seen that tightening the sa (1* screws will-tighten vthe armature'which. must ,be tight enough'to prevent sticking to. the [said polepieces. The

receiver cord tips '15, 15 are connected to' the terminals of the spool winding throughthe washers -16,. 16-- to which they are soldered and thecord tips are held in position by the screws? 17, 17.

-A shell '18- covers the working parts and connects with the'earp-iece 1.

As shown in Fig, lithe armature is a straight ribbon of-iron or steel. This can be modified'by using a'thin'ribbon 19. of some other material with a magnetic armature 20 attached in the central portion as illustrated a in .Figs. 5 and.6.0r,a semiecircular or other shaped diaphragm may be attached or [formed integral with the armature at each end as illustrated in Fig 4.

-I'claim .3

1.- Atelephone receiver comprising adiaphragm surrounded by an actuating'coih'a maghetiiour polepi'ecelimbs connected with said'm'agnet and acting upon said armature, two of said limbs being .connected with one pole of'the magnet and disposed at opposite sides of said-coil and on opposite sides of said armature, and the other two polepiece limbs beingiconnected with the other pole of said magnet and disposed inpositions opposite to the first two polepiece limbs.

2. A telephone receiver comprising an armature adapted to reproduce sound surrounded by an actuating coil; a magnet; four polepiece' limbs connected with said magnet and acting upon said armature, two of said limbs being connected with one pole of the magnet and disposed at opposite sides of said coil and on opposite sides of said armature, and the other two polepiece limbs oeing' connected with the other pole of said magnet and disposed in positions opposite to the first two polepiece limbs.

3. In combination, an actuating coil, and

" a vibratile diaphragm extending through said-coil transversely to the windings thereof, the saidcoil being disposed adjacent the medial portion of said diaphragm, the said diaphragm being subjected to magnetic force also. n

i. A telephone receiver com-prisingan armature adapted to reproduce sound, and an actuating coil disposed about said armature intermediate'the ends thereof. V

5; A telephone receiver comprising a diav phragm supported adjacent two opposite imam;

edges and an actuating coildisposed around 0 8. A telephone receiver comprising a die f phragm, and an actuating coil disposed about-the medial portion thereof, the Wind- 35 ings of said coil lyingtransversely to said diaphragm. r

' NATHANIEL BALDWIN. 

